Europe Oceans 2005最新文献_第3页

Near bottom measurement of wave environment in a tidal current 潮流中波浪环境的近底测量

Europe Oceans 2005 Pub Date : 2005-06-20 DOI: 10.1109/OCEANSE.2005.1511768

A. Williams, A. Morrison

{"title":"Near bottom measurement of wave environment in a tidal current","authors":"A. Williams, A. Morrison","doi":"10.1109/OCEANSE.2005.1511768","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1511768","url":null,"abstract":"Passenger ferries running from Woods Hole to Martha's Vineyard in Massachusetts enter Vineyard Sound at the Woods Hole Harbor entrance and turn from south to east where summer southwesterly winds often set up a short chop. Occasional stronger blows create a swell running across or opposed to the strong tidal current Northeasters are common from October to May and set up a chop and swell at the Martha's Vineyard end of the passage as well as at the turning point off Woods Hole. Directional wave measurements were made for the Woods Hole and Martha's Vineyard Steamship Authority in June and July 2004 to characterize the wave climate for design of a new fast ferry that will serve this route. Heavy boat traffic makes surface buoys at the critical turning region impractical but shallow depths permit a directional wave spectrum to be computed from near bottom measurements of vector velocity and pressure. However the strong tidal currents add a new element to the computational task of projecting near bottom wave velocities back to the surface. In extreme cases, the wave period observed at the bottom may be very long when the waves propagate into the current yet the attenuation relation for waves near the bottom must use the wave period relative to the near surface moving water. This back tracking of current presents a problem that has not been well addressed by existing wave models. In the Vineyard Sound case, shallow depths and unstratified conditions permit a computation of the surface current from the near bottom measurements for this reconstruction.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132812891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Intelligent diagnosis for autonomous underwater vehicles using a neuro-symbolic system in a distributed architecture 基于分布式神经符号系统的自主水下航行器智能诊断

Europe Oceans 2005 Pub Date : 2005-06-20 DOI: 10.1109/OCEANSE.2005.1511739

M. Perrier, J. Kalwa

{"title":"Intelligent diagnosis for autonomous underwater vehicles using a neuro-symbolic system in a distributed architecture","authors":"M. Perrier, J. Kalwa","doi":"10.1109/OCEANSE.2005.1511739","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1511739","url":null,"abstract":"The paper presents the utilisation of a neuro-symbolic system designed and developed for health monitoring and diagnosis of autonomous underwater vehicles (AUVs) within a complete modular and distributed architecture. The neuro-symbolic system, named NSS has been developed within the IST European project ADVOCATE II and is part of the global architecture designed in the project. The paper focuses on the application of the ADVOCATE II solution on two different experimental AUVs: the VORTEX underwater vehicle owned and operated by Ifremer and the experimental MiniC AUV developed and operated by ATLAS ELEKTRONIK GmbH. The paper briefly describes the ADVOCATE II modular and distributed architecture, and presents in detail some study cases for the two underwater applications, and the added-value of such an approach for AUV. The NSS system developed and used within the architecture is dedicated to diagnosis of thrusters and actuators. NSS is a neuro-symbolic system which allow us to simultaneously work on symbolic rules and on neural networks, using transformation techniques. The symbolic rules are compiled at the initialisation of the system into a neural structure, further trained with representative examples. The trained neural network is then used for real-time diagnosis during the AUV mission execution.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131003569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Investigation of thickness effects on 2D NACA symmetric foils 二维NACA对称箔厚度效应研究

Europe Oceans 2005 Pub Date : 2005-06-20 DOI: 10.1109/OCEANSE.2005.1513247

C. Sarraf, R. Jaouen, H. Djeridi, J. Billard

{"title":"Investigation of thickness effects on 2D NACA symmetric foils","authors":"C. Sarraf, R. Jaouen, H. Djeridi, J. Billard","doi":"10.1109/OCEANSE.2005.1513247","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1513247","url":null,"abstract":"A numerical and experimental study on the hydrodynamic behaviour of 2D NACA (15, 25, 35%) symmetric hydrofoils at high chord (/spl ap/10/sup 6/) Reynolds numbers and high angles of attack is performed. The focus is devoted to the comparison between results particularly for stall conditions corresponding to unsteady separated flow. The effect of thickness on the hydrodynamic coefficients and the topology of the flow are studied and the capacity of commercial code to predict the hydrofoil stall by Reynolds-Averaged Navier Stokes equations is analysed. The hydrodynamic coefficients are measured using a force balance and the flow patterns are investigated using LDV techniques. The cavitating incipient flow has been investigated to determine the minimum pressure coefficient and correlations are proposed to join these results to the thickness effect. All the calculations (steady and unsteady) have been performed using FLUENT/spl reg/ code. The emphasis is on turbulence modelling, grid size and boundary layer conditions on the foil. The computation is validated with very detailed experimental data. A hysteretic behaviour of force coefficient is highlighted and the development of leading edge vortices before and after stall occurrence is characterised.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"360 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133046103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Autonomous underwater pipeline inspection in AUTOTRACKER PROJECT: the navigation module AUTOTRACKER项目中的自主水下管道检测:导航模块

Europe Oceans 2005 Pub Date : 2005-06-20 DOI: 10.1109/OCEANSE.2005.1511745

G. Acosta, H. Curti, O. Calvo

引用次数: 18

Buried mines detection and classification: advanced technologies and signal processing 埋地地雷探测与分类:先进技术与信号处理

Europe Oceans 2005 Pub Date : 2005-06-20 DOI: 10.1109/OCEANSE.2005.1511701

M. Amate, A. Hétet, S. Guyonic, M. Legris, R. Bellec, F. Maussang, J. Chanussot, P. Cervenka, J. Marchal

引用次数: 7

Synthesis from underwater data: application to the oceanic discrete tomography 水下数据合成:在海洋离散层析成像中的应用

Europe Oceans 2005 Pub Date : 2005-06-20 DOI: 10.1109/OCEANSE.2005.1511766

L. Cros, C. Ioana, A. Quinquis